Amazon's Alexa Guard Plus subscription service is now live in the US. The company unveiled Guard Plus back in September as a paid option for those who want the extra features that come with the premium version of its free Guard service. While the basic Guard feature can already turn Echo smart speakers and displays into home security devices, its premium version takes things a step further by giving subscribers hands-free access to emergency services and giving Alexa the power to deter intruders from breaking in. Customers who pay for a subscription will be able to ask Alexa to call Emergency Helpline for them to request medical, fire or police assistance. The service also gives Alexa the capability to detect sounds of activity in the house if its residents are away and to sound a siren from Echo devices if it does. Alexa could also play the sounds of dogs barking from the speakers if connected outdoor security cameras detect motion outside the door.

The fourth generation of Amazon's Echo smart speaker marks a radical departure in industrial design, ditching the familiar columnar form factor of previous iterations for something that looks for all the world like a child's bowling ball. Two things haven't changed: The Echo (and Alexa) remain our favorite tools for smart home control, and the company still trails Sonos in terms of building smart speakers that sound great. The recent introduction of the Nest Audio leaves Amazon in third place behind Google in terms of audio performance (don't forget the powerful Google Home Max). Amazon continues to make strides in terms of audio quality, and the fourth-gen Echo sounds very good, especially if you like your tunes leavened with bass. But in a three-way comparison with the Nest Audio and the Sonos One (which, I should note, costs twice as much as either of its competitors), the Echo comes up just a wee bit short, as I'll discuss a bit later.